Is there any more effiecient way to implement this?
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Using MATLAB:I have a table of lets say x(size(100x1)),y(size(100x1)) and z(size(100x100)) and i use
z1 = interp2(x,y,z,x1,x2)
to find a scalar value that i need for later calculation. I was wondering if there is a more efficient/quicker way to implement this.scatteredInterpolant function could help? I tried unsuccessfully to implement it with scatteredInterpolant
2 个评论
per isakson
2014-10-18
"find a value"   should I understand one scalar value?
Dimitrios
2014-10-18
采纳的回答
Mohammad Abouali
2014-10-18
编辑：Mohammad Abouali
2014-10-18
scatteredInterpolant is suitable for cases where your source grid is scattered. If you were able to use interp2 it means that your source grid is not scattered. Although you can still use scattered interpolant, it does not give you any additional benefit.
Here are two approaches:
1) using gridded interpolant:
[XGrid,YGrid]=meshgrid(x,y);
F=griddedInterpolant(XGrid',YGrid',z','cubic');
Then you can query that for any point as follow:
z1=F(x1,x2);
x1,x2 could be scattered points or gridded. If it is gridded it should follow NDGrid format.
2) Using Scattered Interpolant:
[XGrid,YGrid]=meshgrid(x,y);
F=scatteredInterpolant(XGrid(:), YGrid(:),z(:));
Then you can query that for any point as follow:
z1=F(x1,x2);
更多回答（1 个）
per isakson
2014-10-18
编辑：per isakson
2014-10-18
0 个投票
If linear is good enough as you indicate in the question (default of interp2).
My approach to a similar performance problem included
- avoid the function call. The call itself takes longer than the computation (of a scalar)
- a few lines of code, which do the interpolation, directly in the "calling" code.
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